26431261999 has 4 divisors (see below), whose sum is σ = 26441824336. Its totient is φ = 26420699664.

The previous prime is 26431261993. The next prime is 26431262009. The reversal of 26431261999 is 99916213462.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 26431261999 - 2³ = 26431261991 is a prime.

It is a super-2 number, since 2×26431261999² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26431261991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5277414 + ... + 5282419.

It is an arithmetic number, because the mean of its divisors is an integer number (6610456084).

Almost surely, 2^26431261999 is an apocalyptic number.

26431261999 is a deficient number, since it is larger than the sum of its proper divisors (10562337).

26431261999 is a wasteful number, since it uses less digits than its factorization.

26431261999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10562336.

The product of its digits is 1259712, while the sum is 52.

The spelling of 26431261999 in words is "twenty-six billion, four hundred thirty-one million, two hundred sixty-one thousand, nine hundred ninety-nine".